Refrigeration



June 27, 1939. A, R THOMAS REFRIGERATION Filed Oct. 15, 1936 3 Sheets-Sheet l A@ ATTORNEY.

A. R. THOMAS REFRIGERATION June 27, 1939.

Filed Oct. 15, 1936 3 Sheets-Sheet 2 MJ Al/E NTOR.

l@ ATTORNEY.

June 27, 1939. A. R. THOMAS REFRIGERATION Filed Oct. l5, 1936 3 Sheets-Sheet 3 v INVENTOR, a uw# K. TA1/WML ATTORNEY.

Patented June 27, 1939 nEFmGEaA'rIoN Albert R. Thomas, Evansville, Ind., assignor to Servei, Inc., New York, N. Y., a corporation of Delaware Application October 15, 1936, Serial No. 105,682

9 claims. (ci. cs2-119.5)

Myinvention relates to refrigeration, and more 'particularly to refrigeration apparatus of the' absorption type.

It is an-object of my invention to provide an E 5 improved air-cooled absorber for refrigeration apparatus of the absorption type in which the flow of gas in the absorber is counter-current to the flow of air caused to circulate past the absorber. Another object of my invention is to provide ll0 refrigeration apparatus of the absorption type which is so constructed and arranged in a refrigerator cabinet that air is caused to circulate naturally past the absorber in a direction opposite tothe flow of vaporous refrigerant in the l5 absorber.

A further object of my invention is to provide .an improved air-cooled absorber for absorption refrigeration apparatus of the type containing an inert gas, whereby the inert gas flows from a 20 higher temperature point -to a lower temperature point in the path of air flow.

The novel features which I believe to be characteristic of my invention are set forth with particularlty in the claims. The invention, both 25 as to organization and method, together with further objects and advantages thereof, will be better understood by reference to the following description taken in connection with the accompanying drawings of which Fig.A 1 is a side eleva- 30 tion, partly in section, of a refrigerator embodying my invention; Fig. 2 is a sectional view taken on lines 2-'-2 of Figs. 1 and 3; Fig. 3 is a sectional view taken on lines 3-3 of Figs. 1 and 2; and Fig. 4 diagrammatically illustrates more fully I`A-35 refrigeration apparatus of which parts are shown in Figs. 1, 2, and 3.

Referring to Fig. 1, I have shown my invention embodied in a refrigerator including a cabinet I having thermally insulated walls I I deflning a 4,0 Vstorage space I2 into which access may be had by a door I3 hinged to the front of the cabinet. Below the storage space I2 is an apparatus compartment I4 which extends to the rear of the cabinet I9 and communicates with an upward extending Acompartment or ue I5 which also houses parts of the refrigeration apparatus..

The refrigeration apparatus shown is of a uniform pressure absorption type, generally as described `in Patent No. 1,609,334 vto B. C. l50 von Platen and C. G. Munters. Referring to Fig. 4, the refrigeration apparatus comprises a generator I6 having a rear chamber I1 and a forward chamber I8 communicating with an upward extending stand-pipe or separator I9. The 55 generator contains a body of absorption liquid having a suitable refrigerant in solution therein, and, although I do not wish to be limited thereto, the absorption liquid and refrigerant may be water and ammonia, respectively. The generator I6 may be heated in any suitable manner, as by 5 a burner 20, which projects its flame into the; forward end of a horizontal flue 2l which extends through the generator. The heat applied to the generator causes ammonia vapor and absorption liquid in chamber I1 to pass through 10 an opening 22 in the lower end of a small vertical conduit 23 which constitutes a vapor-lift and conducts ammonia vapor and absorption liquid to the upper part of the stand-pipe I9. The

` liberated ammonia vapor entering the stand-pipe l5 I9 from conduit 23, as well as the ammonia vapor` expelled from solutionin the stand-pipe I9 and chamber I8, flows upward through an air-cooled rectifier 24 which condenses water vapor accompanying the ammoniavapor. The water condensed in the rectifier drains back to the gen.-l` erator, and the ammonia vapor flows upward to an air-cooled condenser 25 comprising a coil provided with a plurality of heat dissipating elements y or cooling fins. The ammonia is liquefied in the 25 condenser 25 by surrounding cooler air which flows over the surfaces of the coil and fins, and the liquefied ammonia flows through a conduit 26 into the upper section of an evaporator coil 21 which is below the condenser and arranged within the storage space I2. An inert gas, such as hydrogen, enters the lower section of the evaporator coil 21 from theI outer passage 28 of a gas heat exchanger 29. The liquid ammonia evaporates and diffuses into the hydrogen with consequent absorption of heat" from the surroundings of the evaporator. Thev lower section of the evaporator coil 21 may be arranged closely adjacent to and in heat exchange relation with a shell 30 which is adapted to re- 40 ceive trays for freezing water, as shown in Fig. 1,` and the upper section of the evaporator coil may be provided with a plurality of ns 30a. The

` resulting mixture of ammonia and hydrogen, that is, gas rich in ammonia, flows downward from the evaporator coil 21 through the inner passage or conduit 3l of the gas heat exchanger 29 which is connected at its lower end to the upper part of a vessel `$12. The gas rich in ammonia ows from vessel 32 into the lower end of an air-cooled 50 absorber 33 in which the ammonia is absorbed into lweak absorption liquid that enters the upper part of the absorber through a vertically` extending conduit 34. The hydrogen, which is practically 'insoluble and weak in ammonia, passes 55 upward from the absorber 33 through the outer passage 23 of the gas heat exchanger 23 into the evaporator coil 21. The gas heat exchanger 23 transfers heat from gas which is weak in ammonia and flowing toward the evaporator coil to gas which is rich in ammonia and flowing toward the-absorber 33.` A conduit 35 is connected to the lower part of the evaporator coil 21 and to conduit 3| to drain liquid ammonia from the lower section of the evaporator coil 21.

The absorption liquid owing downward through the absorber 33 in counter-flow to the gas mixture and in intimate contact with the latter becomes enriched in ammonia and flows into the vessel 32 which serves as an accumulation vessel for the absorption liquid. From the vessel 32 the absorption liquid passes through conduit 35 and outer passage 31 of a liquid heat exchanger to chamber I1 of the generator. Liberted ammonia vapor and absorption liquid are causedto flow upward through the vertical conduit 23 into the upper part of the stand-pipe I9, as explained above, to a higher level than it is in the absorber 33; and the absorptionliquid weak in ammonia ows from .chamber Il through the inner passage 38 of the liquid heat exchanger and conduit 34 into the upper end of the absorber 33. A portion of the conduit 34 is provided with a plurality of ns 38 to effect additional cooling of the weak absorption liquid entering the absorber A33.

In order to vary the total pressure in the` refrigeration system just described with changes in air temperature, a vessel 40 for storing hydrogen is provided having the upper part thereof connected by conduit 4| to the lower end of the .not liquefied in the condenser, the ammonia vapor will flow through conduit 4| to displace hydrogen in the vessel 40 and force hydrogen through conduit 42 into the gas circuit.l This' raises the total pressure in the system so that an adequate condensing pressure is obtained for the increased air temperature.

The manner in which the refrigeration apparatus just described is arranged in the apparatus compartments I4 and I5 below and to the rear of the storage space I2 is clearly shown in Figs. 1, 2, and 3, with similar parts designated by the same reference numerals- The different elements or parts and connecting conduits are made of metal and permanently secured together, as byweiding, for example, to provide a hermetically'closed system. The generator I5, liquid heat exchanger, and stand-pipe I9 are prefer; ably enclosed in a shell, indicated by a dotted line 43 in Figs. 1 and 3, which contains a body 44 of suitable insulating material, as shown diagrammatically in Fig. 4.

The shell 43 is arranged in the lower part of thea'pparatus compartment I4 with the upright lportion thereof extending upward into the lo'wer part of the rear apparatus compartment I5. The pressure vessel 4I) is disposed in the rear apparatus compartment. and above the latter are positioned the air-cooled rectifier 24 and aircooled condenser 25. 'I'he rear wall 4 5 of the. refrigerator terminates at the lower end of the condenser 25 and deects inwardly, as indicated at 45,

Adjacent to the condenser 25L the rear wall of the storage compartment is provided with an opening having a removable wall part or cover 41 whereby the evaporator coil 21 can readily be placed in position within the storage space when the cover 41 is fitted into the opening. The gas heat exchanger 25 is disposed in the rear insulated wall of the storage space I2.

The ilue 2| of the generator I3 is bent adjacent to the rear wall 45 of the refrigerator and extends upward into the lower part of the rear apparatus compartment I5. The vertical portion 48 of the flue 2| serves as an off-take duct for the products of combustion of the burner llame and 4is flared outward with the upper discharge end thereof substantially rectangular in section, as shown in Fig. 2.

During operation of the refrigeration apparatus, the temperature -of the air in the rear apparatus compartment l5 is considerably higher than that of the air surrounding the refrigerator, due -to the hot products of combustion of the burner fiame discharged from the olf-take duct 48. This produces a natural draft in the apparatus compartment I5 and causes an upward circulation of air in the manner indicated by the arrows of Fig. l. The upward circulation of air is also partly caused by the heat radiated by the air-cooled rectifier 24 andair-cooled condenser 25 which are preferably positioned adjacent the outlet of the air flue and above the rear wall 45, so that surrounding `cooler air can flow directly over their surfaces and assure adequate cooling of these parts of the refrigeration apparatus.

The continuous circulation of hydrogen inthe air-cooled absorber 33 which is 'so constructed and arranged that the gases circulated there' through are in .counter-flow to the 'air passing over the surfaces of the absorber, so that the latter will operate emciently to absorb vaporous refrigerant into absorption liquid. `The absorber 33 comprises two inclined conduits 45 and 53. arranged alongside each other, the conduits being relatively wide compared to their height and substantially rectangular in section to provide a relatively large heat Atransfer surface. The upper ,end of conduit 49 is connected by means of a` Y cross conduit 5| to thev lower end of conduit 5l.

as shown most clearly in Fig. 2., the conduits in effect forming a single conduit including straight portions and a bend to provide a vessel having an inlet and outlet at different elevations. A u

I2 and the top horizontal portion of the shell 43. 75

The uppermost conduit 50 of the absorber is positioned at the forward end of the lower apparatus compartment and to the upper end thereof is connected the vertical conduit 94 through which weak absorption liquidflowing from the generator I5 enters into the absorber, as shown in Fig. 3. To the upper end of conduit 50 is also connected a conduit 54 which is connected at its upper end to the lower end of the outer passage 29 of the gas heat exchanger 29, as shown in Figs. 2 and 3, through which conduit 54 passes gas flowing from the absorber to the evaporator coil 21. 'I'he lower end of conduit 49, which is positioned to the rear of conduit 59, is directly connected to the upper partv of the vessel 32 which diifers in Fig. 3 from the vessel 32 diagrammatically illustrated in Fig. 4 in that the top of the vessel is shown concave-shaped with the lower end of the inner conduit Il of the gas heat exchanger 29 connected to the top of the vessel rather than to the side of the vessel.

It will now be understood, in view of the description of the apparatus given above in connection with Fig. 4, that weak absorption liquid is introduced into the upper end of the -forward conduit 5|! and flows downward therein and through the cross conduit 5I and rear conduit 49 into the storage vessel 32. The gas mixture which is rich in ammonia, on the other hand, flows from the vessel 92 through the rear conduit 49, cross conduit 5I, and forward conduit 50 from which it passes through conduit 54 into the outer passage 29 of the gas heat exchanger 29. The gas mixture in the absorber, therefore, rst ilows through the rear conduit 49 and then through the forward conduit 59 of the absorber in a direction counter-current to the substantially horizontal flow of air in the lower apparatus compartment I4, as shown in Fig. l. A baille plate 55, which extends between the side walls of the refrigerator and from the rear wall 45 to the forward part of the absorber 33, is positioned directly beneath the absorber. In this manner a passageway is provided for the absorber 33 whereby all of the air caused to ow upward in the rear apparatus compartment or flue I5, as explained above, must first pass over the surfaces of the conduits 49 and 54 and fins 52 and 53 secured thereto, as indicated by the arrows in Fig. 1. The air passing over the heat transfer surfaces of the absorber 93 adjacent the inlet of the air flue is heated and further augments the heating of air effected in the rear apparatus compartment i5,

to cause an upward circulation of air which is extremely effective to withdraw heat rejected from the different parts of the apparatus which are arranged to be air-cooled.

By providing two groups or banks of ns on the absorber 39 which are out of alignment and inclined with respect to each other, the path of travel of the air is changed whereby a twisting or stirring of air is eil'ected to insure good heat transfer from the heat dissipating surfaces provided by` the absorber. With the circulation of the gas mixture in the absorber in counter-now to the circulation of air past the absorber, an extremely eilicient absorber is provided in which the vaporous refrigerant is effectively absorbed into the absorption liquid, thereby improving the eillciency of the refrigeration apparatus. Further, by positioning the absorber in a passageway formed in they lower apparatus compartment i4 in the manner shown and described, the circulation, of air caused by the discharge of the products of combustion of the burner flame and the rejection set forth, and I intend in the following claims tol cover all modifications which do not: depart from.

the spirit and scope of my invention. What is claimed is:

1. Refrigeration apparatus comprising struc-y ture forming a vessel provided with a relatively large heat transfer surface, conduit means for introducing a gas including vaporous refrigerant and absorption liquid into said vessel, means adjacent to said structure forming a laterally extending passageway for air, means for causing air to flow through said passageway. Said structure and conduit means being so constructed and arranged to provide lateral flow of gas in said vessel and from a point of higher air temperature to a point of lower air temperature in the path of flow of air past said structure.

2. Refrigeration apparatus comprising a conduit including straight portions and a bend and having an inlet and outlet at different elevations, members for introducing gas and liquid into said conduit, a plurality of heat dissipating elements secured to the straight portions of said conduit, said conduit being arranged with the inlet and outlet in slightly different vertical planes whereby gas and liquid flowing therethrough are conducted in a substantially horizontal direction, and means for causing air to flow substantially horizontally past said conduit and said elements secured thereto in a direction such that the gas in said conduit flows from a point of higher air temperature to a point of lower air temperature.

3. Refrigeration apparatus comprising a conduit including straight portions and a bend and having an inlet and outlet at different elevations, members for introducing gas and liquid into said conduit, a plurality of heat dissipating elements secured to the straight portions of said conduit, said conduit being so formed and arranged that the straight portions thereof are disposed alongside each other in substantially a horizontal plane whereby gas and liquid flowing therethrough are conducted in a substantially horizontal direction, and means for causing air to ow substantally horizontally past said conduit and said elements secured thereto and in a direction such that the gas in said conduit flows from a point of higher air temperature to a point of lower air temperature.

4. A refrigerator comprising a cabinet provided with a thermally insulated storage space, a vertically extending air ue disposed adjacent to said storage space and having an inlet below said storage space and an outlet above the inlet, an absorber arranged at the inlet of said ue and comprising a conduit including straight portions and a bend and having an inlet and outlet at different elevations, members for introducing gas and liquid into said conduit, a plurality of cooling ns secured to the straight portions of said conduits, said conduit being so formed and arranged that the straight portions are substantially in a horizontal plane whereby gas and liquid flowing therethrough are conducted in a substantially horizontalA direction, and means including said absorber for causing air to ilow substantially horizontally past said conduit in a direction such that the gas in the conduit is first in one straight portion in heat transfer relation with air which has been warmed by 'dissipation of heat from another straight portion and then in such other straight portion in heat transfer relation with cooler air, said cooling iins forming a plurality oi passageways extending substantially in the direction of air iiow.

5. In an absorption refrigeration system, members forming a natural draft ilue having a lateral section and a vertical section behind the lateral section in the path oi' travel of air in the flue, an absorber having a iirst tubular branch in said lateral ilue section and a second tubular branch in said lateral ue section behind the rst tubular branch in the path of air flow and connected thereto in series, an evaporator, means to conduct a gaseous medium including an inert gas from said evaporator to said second tubular branch and from said first tubular branch to said evaporator, a generator, means to conduct weak absorption liquid from said generator to said ilrst tubular branch, and means to conduct strong absorption liquid from said second tubular branch to said generator, whereby inert gas flows from a higher temperature point to a lower temperature point in the air flue.

6. In an absorption refrigeration system, members forming a laterally extending air passage, means to cause flow of air in said passage in a given direction, an absorber having a ilrst tubular branch in lsaid passage and a second tubular branch in said passage behind the iii-st tubular branch in the path of air flow, said branches being connected in series, an evaporator, means to conduct a gaseous medium including an inert gas from said evaporator to said second tubular branch and from said rst tubular branch to said evaporator, a generator, means to conduct weak absorption liquid from said generator to said ilrst tubular branch. and means to conduct strong absorption liquid from said second tubular branch to said generator, whereby inert gas flows higher branch, and means to cause cooling air to` flow in contact with said branches and to direct said air so that the .maior part of unheated air contacts the branch of higher elevation.

8. In an absorption refrigeration system, an,

absorber including a plurality oi tubular branches disposed substantially side by side and laterally of each other and having a generally downward slope for gravity ilow of absorption liquid, one branch having an average elevation higher than another branch, means to cause flow of inert gas and refrigerant vapor from a lower branch to a higher branch, and means to cause cooling air to flow in contact with said branches and to dlrect said air so that all of the air first contacts a branch of higher elevation and thereafter a branch oi' lower elevation.

9. Apparatus as set forth in claim 6 in which the tubular branches are provided with separate groups of iins arranged in series with respect to;

air iiow.

' ALBERT R. THOMAS. 

